Apparatus for starting and operating gaseous discharge devices



Dec. 11, 1956 A. E. FEINBERG APPARATUS FOR STARTING AND OPERATING GASEOUS DISCHARGE DEVICES 5 Sheets-Sheet 1 Filed Oct. 13 1951 L2 F. I:\\ 5

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APPARATUS FOR STARTING AND OPERATING GASEOUS DISCHARGE DEVICES Filed Oct. l3 1951 5 Sheets-Sheet 2 2303 ll 61/ El ar/Z I fi wuj a Dec. 11, 1956 A. E. FEINBERG 2,774,010

APPARATUS FOR STARTING AND OFERATING GASEOUS DISCHARGE DEJCES Filed Oct. 13. 1951 5 Sheets-Sheet 3 Dec. 11, 1956 A. E. FEINBERG 7 APPARATUS FOR STARTING AND OPERATING GASEOUS DISCHARGE DEVICES Filed Oct. 15, 1951 5 Sheets-Sheet 4 Dec. 11, 1956 A. E. FEINBERG APPARATUS FOR STARTING AND OPERATING GASEOUS DISCHARGE DEVICES Filed Oct. 13, 1951 5 Sheets-Sheet United States Patent APPARATUS FOR STARTING AND OPERATING GASEOUS DISCHARGE DEVICES Albert E. Feinberg, Chicago, 11]., assignor to Advance Transformer Co., Chicago, 111., a corporation of Illinois Application October 13, 1951, Serial No. 251,197

21 Claims. (Cl. 315-138) This invention relates to apparatus for starting and operating gaseous discharge devices, such as for example fluorescent lamps utilized for illuminating purposes.

It is well-known that gaseous discharge devices have negative resistance characteristics in that although there is substantially no flow of current when the device is not ignited, once the device has been ignited there is a relatively great drop in internal resistance such that the current which will be drawn by the device increases without limitation. Unless the device is in some way prevented from doing so, it will destroy itself through passage of heavy current. Ignition consists of ionization of the gas within the device causing the same to become conductive.

The apparatus with which this invention is concerned provides a high voltage for starting the device, and a lower voltage after the device has been ignited, with sufficient impedance to limit the current flowing through the device during operation thereof. usually required to be energized from ordinary electric lines and hence provide transformation of some type to achieve the necessary high voltages.

Although not limited thereto, the apparatus of the invention is intended to be used with fluorescent lamps and is generally called a ballast. In the case of the conventional lamps which utilize thermo-acting starting switches, the voltages required are much lower than those required for the so-called instant start lamps. This invention is directed to the construction of apparatus of the latter type, and to a solution of the problems arising by virtue of the higher voltages thereof. The apparatus which will hereinafter be described is especially suitable for use in installations utilizing from one to three devices, all operated from the same ballast.

The invention relates to a type of apparatus shown, described and claimed in U. S. Patent No. 2,558,293, the patentee and title of which are the same as those of the instant application. The principal object of the invention is to provide a modified form of the invention .of the said Patent No. 2,558,293 having certain additional features.

Another object of the invention is to provide apparatus of the character described for igniting and thereafter providing the operating voltage for one or a plurality of gaseous discharge devices in which the windings thereof may be mounted on laminations of simple and conventional form.

Still a further object of the invention is to provide apparatus for igniting and thereafter providing the operating voltages for gaseous discharge devices which will be very quiet.

A further object of the invention is to provide a novel and improved ballast for gaseous discharge devices in which the devices will be ignited seriatim and will thereafter operate substantially as though in series.

A further object of the invention is to provide a device of the character described in which there is provided an auxiliary starting winding which will develop very Such apparatuses are high voltage upon starting but which will thereafter develop high reactive impedance such that very little current will flow therethrough during operation. As a result of the achievement of this object, the said winding (or group of coils) may be formed of a great number of turns of very fine wire, resulting in saving of copper, iron, and space.

Still another object of the invention is to provide apparatus of the character described in which there is an auxiliary starting winding (or group of windings), said winding having two sections, one relatively closely coupled to the primary and acting as a secondary of said primary, and the other section being without the magnetic circuit affected by the primary, and acting as a choke whereby the size of the principal magnetic circuit is decreased materially.

Many other objects will occur to those skilled in the art to which this invention appertains. It is desired to point out that many advantages which will emphasize the contribution I have made to the arts and sciences are not specifically enumerated since same will be obvious from the description of the preferred embodiments.

In connection with these descriptions, which are not by way of limitation but only for illustration as required by the patent statutes, the same figures of reference will be used to designate the same or equivalent structural elements or diagrammatic components throughout the several figures of the drawings in which:

Fig. l is a schematic electrical diagram showing a circuit in which my invention has been embodied in apparatus for igniting and operating two gaseous discharge devices, designated here as fluorescent lamps.

Fig. 2 is a semi-diagrammatic representation in the form of a sectional View through a ballast the construction of which is in accordance with my invention, the same being suitable for use with the circuit of Fig. 1 and others described hereinafter.

Fig. 3 is a vector diagram utilized in connection with one explanation set forth below and describing what I consider the theory of operation of the invention.

Fig. 4 is a view similar to that of Fig. 2 except of a modified form, difiering therefrom only in the manner of orientation of certain of the windings.

Fig. 5 is a schematic electrical diagram showing a diiferent form of the invention embodied in a circuit of the type shown in Fig. 1.

Fig. 6 is a schematic electrical diagram substantially the same as that of Fig. 5, except that the primary winding and the secondaries are connected in straight conventional transformer relationship as opposed to autotransformer relationship which is the case of Figs. 1

- and 5.

Fig. 7 is a semi-diagrammatic representation in the form of a sectional view through a ballast the construction of which is in accordance with my invention, the same being suitable for use with circuits such as illustrated in Figs. 8 and 9 for igniting and operating three gaseous discharge devices.

Figs. 8 and 9 are schematic electrical diagrams showing circuits in which my invention has been embodied in apparatus for igniting and operating three gaseous discharge devices, and which may utilize the core structure shown in Fig. 7.

Figs. 10 to 13 inclusive are schematic electrical diagrams showing circuits in which my invention has been embodied in apparatus for igniting and operating single gaseous discharge devices, the respective circuits differing one from the other in respect to the manner of connection of the components thereof.

Fig. 14 is another schematic electrical diagram show I ing a two-device circuit of modified form.

aye-mono Fig. 15 is a view similar to that of Fig. 17 exceptthat the core structure illustrated is suitable for use in connection with the circuit of Fig. 14 and is embodied in a type of ballast suitable for assembly as a ,brick .structure.

:Fig. 16 is a view similar to that of Fig. 15, except show ing a modified form of construction.

The generic concept of my invention comprises a mod1- fication of the apparatus of the aforementioned U. Patent No. 2,558,293 in a manner giving rise to certam advantages. The apparatus of my previous patent included a primary winding P, a first secondary winding S1 sometimes described as an auxiliary starting secondary, and a second secondary winding S2. The first secondary winding S1 is of importance principally in igniting the Tfirst gaseous discharge device connected with the apparatus, since it develops high leakage reactance after such .ignitionla-nd passes very littlecurren't. It is wound with a great many turns of very fine wire and thereby is able to develop a high voltage in a small space and utilizing very little copper. In (times of international stress, such as presently, the smallest savings in vital materials of this nature is of great importance.

The secondaries S1 and S2 in the apparatus of the said .-pa-tent are arranged in voltage bucking relationship-but after ignition of the first gaseous discharge device, there is believed to be a resultant voltage developed in S1 whose phase is additive relative to the voltage of S2 such that the combined voltages of S1 and S2, together with the voltageof the primary in certain cases, is sufiicient to ignite the second gaseous discharge device. Thereafter, the high impedance of the secondary S1 causes current substantially to by-pass the same so that the resulting current flow is in series through the lamps and at least the secondary S2. 7

The same theory of operation holds for the instant invention with the exception that '1 form the secondary winding S1 into two sections which I designate hereinafter Si and S1. Whereas in the case of the above mentioned patent the first secondary winding S1 was loosely coupled with the primary P, in the instant invention the secondary winding S1 is closely coupled with the primary winding P, while the second section of the first secondary winding; namely S1 is in an entirely separate magnetic circuit. It is not'a secondary winding in any sense. Thus no voltage is developed in the winding S1 during starting, whereas after starting, there is a high inductive reactance provided thereby with a voltage so arranged to be additive to the second secondary winding S2 to cause ignition of a second gaseous discharge device. The Winding S1 is mounted on a separate core, much as a choke, but associated in the same container with the other iron, core mounting P, S1 and S2.

The modification described enables me to use simple EI laminations and other commonly available laminations in obtaining many of the advantages of the said patented invention. Thus, the core supporting the three windings has been formed from conventional la'minat'ions used in the industry for ballasts for single 40 watt gaseous discharge devices, and known as single 40 laminations. The laminations of the additional choke may be conventional E-1 laminations of a comparable size.

.Prior to entering into the specific description of the apparatus illustrated it is well to point out that the ballasts of the invention are principally intended to be operated from'the usual 110 to 118 volt A. C. line, and that they need be constructed to provide igniting voltages of the order of several times the line voltage. Likewise, the operating voltages in certain cases will be at least one 'or more times the line voltages. The examples specified in theabove mentioned patent, and as Well in other patent applications which hereinafter will be referred-to give such proportions and specific wire and element characteristics to enable the artisan to construct the same afterreadin'g and understanding the invention from the specification herein set forth.

Referring now to Figs, 1 and 2, the reference character 7 10 designates generally the ballast or apparatus, the electromagnetic portion 20 of which, as will be noted in Fig. 2 is formed of two parts designated the transformer 21, and the choke 22. There is provided a rectangular shell 23 formed of laminations of electrical steel, suitably stacked and fastened together. At the center thereof are provided inwardly directed extensions 2 which stop just short of the sides of a centrally mounted winding leg 25 to form air gaps 26. The gaps and extensions together serve as a magnetic shunt '27 in the center of the transformer section 21. s s v The central winding leg is formed of electrical steel laminations and may seat in suitable recesses in the end bridges of the shell 23. The seating joint at the right end is shown closed as at 28, while the joint formed at the left hand end rnay provide an air gap 29 the size of which provides some measure of control of magnetizing current, It is my practise to wind the windings, presently to be described, upon 't'he central winding leg 25 and thereafter force the assembledjwinding leg and windings into, the center of the shell 23, in a rectilinear movement. This is done, for example, on an arbor press.

Referring now to Fig. '2, note that I have wound the winding S2 upon "the left side of the winding leg 25, and the windings P and Si on the right hand side thereof. Since the windings P and S1 are wound on top of one another, they .are closely coupled and there is substantially no leakage reactance developed in the winding S1 during operation of the device 29. On the other hand, the shunt 27 between the second secondary winding S and the remainder of the transformer 21 gives rise to some leakage 'rea'ct'anc'e in winding S2. 7

It is to bejun ders'tood that although I have stated above that I fwind 'thewfinding's upon the Winding 'leg 25, actual practise, and for high speed commercial production, these windings are pie-formed and in pre-formed condition assembled upon the said windingleg. Attentionis now invited 'to Fig. l, in which the electrical circuit of the apparatus 10 is depicted. v

There is illustrated a group of windings so related as to give rise to the advantages of the invention.v In order to render the circuit diagram lucid, theconventional symbols designating iron cores and shunts .have been omitted, but it "should be understood that such iron cores and shunts are actually present, as explained in connection with Fig. 2, and with other figures of the drawings. 7

The primary vv'inding P of app'aratuslti is provided withe'lectrical leads 31, and 32 by which the said primary winding P is connected across the line tern-finals 3 3 and 34 respectively. The line may be a source of .A. C. voltage, say 11 8 volts, commercially available. There is proyid'ed a first secondary winding 81 which is closely coupled with'the primary windingP and connected in add i tive volta'g'e rela' ship therewith The first secondary winding S1 is provided with leads 35 ;and 36, the ,fir st of which is connected to lead 32 at juncture 37 and the S1, will likewise pass. fllerethrough. w Likewise voltages developed ,Si and be combined to determine the voltages in difiere'n't parts of the apparatus 10 which would otherwise depend only uponthe etfect of winding S1. ,For the purpose oi this specification, the combined windings S1 and Si 7 can .be termed an auxiliary {starting winding for-flied f s n w W ;S .?Pd.-h9 ing: ing S1'. Asindi upon the central fq' lj 1 f E- mm twns. stacked and fastened together with a non-magnetic gap 41 between the leg 41 and the stack of I laminations to increase the inductance of the choke. 'Ihe winding S1 is therefore a high inductive reactance winding, in series with the first secondarywinding 81. Its electrical efiect will become apparent when the explanation of operation of the apparatus is made hereinafter.

The high inductive reactance winding S1 has leads for connecting same into the circuit, one of which is common to the lead 36 and the other of which is designated 42.

The second secondary winding S2 is separated from the primary winding P physically by means of a relatively small magnetic shunt 27 which gives rise to leakage reactance in the winding S2 during operation so that same may serve as an impedance in the current flow path of the gaseous discharge devices. It is connected into the circuit by leads one of which is common to lead 42' and the other of which is designated 43.

With respect to the voltage sense of the windings P, S1, S1, S2 arrows have been used to designate the same. The solid arrows denote the open circuit voltage sense or direction. Since there will be no voltage developed in the choke 22 on open circuit, its voltage arrow is designated with broken lines. The primary and first secondary windings P and S1 are wound in the same direction so that their voltages are additive, and the second secondary winding S2 is reverse wound relative to the other two of the transformer windings, so that its voltage sense is bucking. It should be apparent to those skilled in the art, that in the manufacture of apparatus of this kind, the coils are all wound on the same kind of winding machines and these machines wind the coils in the same direction. The reverse volta e arrangements are obtained simply by suitably reversing the lead connections.

I have illustrated two gaseous discharge devices in the form of fluorescent lamps L1 and L2. For the purpose of this specification, these lamps may be considered as capable of rapid ignition. Commercially they are known as instant start lamps. They require high ignition voltages and operate at high voltages. For example, a watt T-l2 lamp 48 inches long will ignite at approximately 450 volts, and operates at a voltage of approximately 140 volts. A 75 watt T-l2 lamp 96 inches long will ignite at approximately 625 volts, and operates at a voltage of approximately 195 volts. These are hot-cathode types of lamps in which there is no need for pre-heating of the filament.

The lamp L1 has leads 44 and 45. The lead 44 is connected to lead 31 at juncture 46, and the lead 45 is connected to the lead 42 at the juncture 47. There is a condenser C in series with the lead 45. The condenser lowers the total reactance of the lamp circuit involving lamp L1 to increase the current flow after starting so that a greater voltage may be produced by the winding S1 to assist in igniting the second lamp L2. The lamp L2 has leads connecting same to the apparatus, one of which is designated 48 and is connected to lead 32 at juncture 49, and the other of which is common with lead 43.

It will be obvious from an examination of the circuit, that the windings are all connected end to end in the order P, S1, S1 and S2. This may be considered a physical series connection, although technically it may not be an electrical series connection since the same currents do not fiow through all windings one after the other. Also, it will be obvious from the circuit that the lamp L1 is connected across the first three of these windings, while the lamp L2 is connected across the last three of these windings. The windings common to both lamp circuits are S1 and S1, which we have chosen collectively to term the auxiliary starting winding.

The general theory of operation is as follows: When the primary P is energized, it induces a voltage in S1 additive thereto, and a voltage in S2 in operation thereto. Since the choke 22 is not in the same magnetic circuit with theprimary P, there will be no voltage induced in the wind ing S1. The sum of voltages across the lamp L2 is the vectorial sum of the voltages induced in S1 and S2 which,

since these secondaries are in opposed voltage relationship, is insufiicient to ignite lamp L2. The sum of voltages across the lamp L1, however, is the sum of voltages in P and S1 which is sufiicient to ignite lamp L1. There will be no current flowing on open circuit in the loop of lamp L1 or winding S1. 7

When the lamp L1 is ignited current commences to flow in its loop, which includes leads 44, primary winding P, secondary winding S1, choke winding S1, leads 45, and condenser C. There is a voltage-produced due to this flow of current in S1 whose voltage sense is indicated by the broken line arrow, and which, as will be noted, is now reinforcing the voltage induced in S2. The condenser C produces a voltage which counteracts the reactive voltage drop of the choke winding S1 so that the resultant voltage will be more nearly in phase with the voltage of the winding S2 such that the vectorial addition of the voltages of S1 and S2 will be suflicient to ignite the lamp L2.

When lamp L is ignited, the branch of the device defined by the auxiliary starting winding S1 and S1 will have greater impedance to current flow than the branch defined by the lamp L1 and the condenser C. Consequently the major flow of current will be as follows: starting with juncture 37, lead 48, lamp L2, lead 43, winding S2, juncture 47, condenser C, lead 45, lamp L1, lead 44, juncture 46. The resulting circuit is therefore in eifect a series circuit in which the inductive reactance of the secondary winding S2 is somewhat balanced by the capacitive reactance of the condenser C so that the efiect on line power factor may be made low. Furthermore, the device is connected with its components in auto-transformer relationship to keep the copper and number of turns low, resulting in considerable savings. The ignition of the lamps seriatim'places no undue load on the primary and does not tax the insulation of the-apparatus.

For an explanation of the device considering voltage vectors attention is invited to Fig. 3. In Fig. 3, the voltage vectors AF and PB are in phase representing respectively voltages in secondary winding S1 and in the primary P. This will be the igniting voltage for the lamp L1, equal in extent to the vector AB. Once lamp L1 has ignited current will flow giving rise to voltages in the loop produced by S1, C, and thewindings S and P. Since the resultant in the loop must equal the voltage across lamp L1, namely vector AC, it will be the sum of condenser voltage represented by the vector DC directed downward to designate inductive voltage, and the other voltages in the loop. The vector AD represents the resultant sum of voltages in S1, P, and S1.

It is noted, however, that the voltage which will appear across the lamp L2 does notinclude any part of the voltage in the primary P. Hence considering the voltage sum of S1 and S1 we obtain another vector. In order to accomplish this graphically, the vector BD can be moved along the diagram to the position indicated by the broken line- FD. Obviously FD and BD are identical. The new vectorial sum is AD. It should be noted that this appears at a substantially greater phase angle relative to the sum of the voltages of S1 and-P, namely. the vector AB. It will therefore be additive to the voltage of S2, which as will be seen is the vector AG, opposite in phase to voltage of S1, vector AF. Finally the sum of the voltages of S2 and AD will give the igniting voltage for lamp L2, vector AE, which can be seen as quite substantial.

In studying the vector diagram, note that on open circuit, the voltage across the lamp L2 was equal to the sum of the voltages of S1 and S2 or the vectorial addition of AG and AF. This is a relatively small voltage- Note also that the condenser voltage DC serves to increase the length of the vector BD, making more voltage available for use in igniting the second lamp L2.

The construction of the commercial ballast embodying the invention involves the assembly of the components deseribedinto a mast container, the inter-eon nfection of the leads with one another in proper 'felation, the connection of condensers,- both of the type 'desig nated C in the drawings and other ty es to eliminate radio interference, the interconnection of high Glin'iage' resistors across the condensers to prevent charge retentiori, and other steps well-known. The two units illustrailed as the choke 22 and the transformer 21-, are arranged side by side physically, and hence there is no problem in connecting the leads thereof to conform to the scheme set forth herein. The units 21 and 22 are covered with somefhighly insulative varnish which may be baked on,- and the entire container filled with an insulative pitch or resin,- with only the leads protiudiiig. Suitable instructions for cont sting the same to the gaseous discharge devices and the line may be carried upon the container.

In certain other cases, the entire apparatus may comprise an illuminating system in which the aseous dis charge devices are provided as a part of the article sold,

but it should be understood that the invention is not limited to the provision of a system including gaseous discharge devices, but rather contemplates such systems as a phase of the invention in addition to the apparatus adapted for use with the said discharge devices.

In Fig. 4 I have illustrated a form of the apparatus 20 which is depicted in Fig. 2 but with certain modifications that in no way affect the operation of the device. In practically all respects the transformer 21 and choke 22 are identical, except that the windings P and S1 are not wound on top'of one another as in the embodiment show'n'in Fig. 2. Instead they are arranged side'by side. T he electrical efiect one upon the other will be the same, and the other parts of the apparatus act as described above.

figure. Instead of providing the air gap 29 at the left handend of the winding leg 25, the magnetic connection th'ereat is direct as shown at 29 The amount of magnet izi'ng current may be adjusted in other ways, such as variation "of physical constants of the transformer compohe'nt s'.

In Fig. 5 I have illustrated a modified form of the invention which differs from the embodiments described in certain minor respects. As in the case or the app'aratus 10 of Fig. 1, either of the transformer constructions of Figs. 2 and 4 may be used. There are provided the primary winding P, an auxiliary starting winding comprising two sections, the first secondary winding S1 and the high inductive 'reactance choke winding S1, and the secondary Winding S2. same reference characters of 'Fig. 1 are used with the prefix 1 to designate the same or similar elements. The apparatus-is designated generally 10!).

The primary winding P is connected across auA. C.

liue'whosevoltage will be substantially less'than the ignition voltage of the gaseousdischahge devices, and which may even be less than "the operating voltages of the discharge devices. For this purpose the winding P is provided with electrical leads 131 and 132, connected respectively to the'line terminals 133 and 134. As in-th'e case of the apparatus ofdig. 1, the remaining windings are connected end to end, i. 'e., one after the other, in the sameorder as those of Fig. 1. The fiist secondary win-ding S1 has 'leads 135and 136,135 of which is connected to the lead 132 at juncture 137. Lead 136 connects between windings S1 and S1, these two'wi'ndings being electrically in series and together forming the auxiliary starting winding. The second side of Winding S1 is provided with'ale'ad'142 connecting same 'with'the second secondary winding S2.

The two lampsLi a'nd'L2 are connected in a somewhat dififerent manner-from-Fig. 1. Lamp 1.1 is connected only across the auxiliary 'starting winding sf-f-sl hnd thus i s provided with Jainism-21111 45, the first or which is joined to -lead 132m juncture 1415, and the second of Another modification is illustrated in the same Insofar as practical, the

sufiicient to ignite lamp L2.

8 which is connected to the lead 142m juncture 147. The condenser C is in series with lead 145. As for the lamp L2, it onnec-ts across all of the windings'and hence its issue 143 and 14 3 are connected'respectively with the free terminal of the winding S2 and lead 131 at juncture 149.

The voltage relationships between the windings are diiferent in this apparatus from those of the apparatus of Fig. 1, but theoperation is the same. Thus, the voltag'e senses of windings P and S2 are such as to reinforce one another, while the voltage sense of the first secondary winding S1 is in opposition to that ofthe primary. This arrangement ofvoltages is obtained by suitable choice of Winding connections, and the relative directions of the voltages are indicated by the solid arrows. The apparatus has a few features which are common to both of the em bodiments of Figs. 1 and 5. First, the voltage relation When the primary P is energized, there will be sufli- I cie'nt voltage induced in the secondary S1 in and of itself to ignite the lamp L1. Neither C nor S1 contribute'to this starting voltage. Once lamp L1 has ignited, the voltage resultant of that produced in S1, C, and S1 will be such that it will add to the voltages induced in P and S2. The sum will be 'sufficient to ignite lamp L2. The sum will be tim. choke winding S1 greatly will limit the current flowing in the auxiliary-starting winding S1S1' such that the principal current path will be a series circuit through the lamps L1 and L2, and the secondary S2. It is not believed necessary further 'to trace this path.

This circuit provides good power factor correction also, and although somewhat different in arrangement from Fig. 1, the principles of operation, the advantages achieved, and the efiicie'ncy are substantially the same.

In Fig. 6 have illustrated another form of the apparatus '10 which is designated generally by the reference character 260. The apparatus 200 differs only in one respect from the apparatus 106 of Fig. 5. Whereas in Fig,

5, apparatus is connected as an auto-transformer, the apparatus 2% of Fig. 6 is connected as a straight transformer. The voltage of the primary P is not utilized to assist in starting either of the lamps, and during operation, current flowing through the lamps L1 and L2 need not pass through the primary winding P. This is best emphasized by noting that the left hand lead of the lamp L2 connects with the right hand side of the primary P.

The reference characters of Fig. 6 which designate elements similar to those of Fig. l differ only by the addition of the prefix 2 to assist in making the comparison between'the apparatus 10 and 200. Thus, thesame windings-P, S1, and S1, and S2 are illustrated. The leads 231 and 232 of the primary P connect with the A. C. line 233 and 234. The leads of the winding S1, namely 235 and 236 connect respectively with the juncture 237 on lead 232 and one terminal of choke winding S1. The winding S2 has leads 242 and 243, the first of which connects with winding 81' and the second of which-conmeets with lamp L2. The opposite terminal of lamp L2 connects via lead 248 with lead 232 of winding P-at juncture 249. The lamp L1 is connected between juncture 247 and juncture 249 by leads 245 and 244, with the condenser C in series with lead 245.

The-enengization of the primary P will result in suflicient voltage being induced inthe secondary S1 to ignite the lamp-L1. When lamp --L1 -i;s.-ign-ited,' voltage developed i n'S reenforces voltage-induced in 52 such that thesum issnificien't to ignite lamp L2. Note that-the voltage di- Thus the lamps ignite seria-. in addition, the high inductive reactance of the rections indicated show S1 and S2 in pilosition. The voltage of S1 reenforces S2 after ignition of L1. No voltage sense symbol is used alongside the primary P, because its voltage is not used to help ignite either lamp. The lead 248 connects with the right hand side of the primary P. T he principal current is a circulating current in loop including lamps L1 and L2 and the secondary S2.

As in the previous embodiments described, the apparatus 200 is a seriatim starting series operating ballast.

In Fig. 7 I have illustrated a form of the transformer part of the invention which is suitable for use in connection with the multiple lamp ballasts 300 and 400 illustrated respectively in Figs. 8 and 9. Basically, these apparatuses include the circuits of apparatus 10 illustrated in Fig. 1, with additions and modifications. Instead of the winding Sz, two series windings Sc and Sx are provided. In addition, there is another secondary St. in closely coupled relationship with Sx for operating a third lamp.

Referring to Fig. 7, there is depicted a magneuc assembly 320, the parts 321 and 322 of which compnse respectively a transformer and a choke. Although eventually assembled in the same metal container, along with other elements of the apparatus, the parts 321 and 322 are magnetically independent. The transformer 321 is formed as a rectangular shell 323 and central winding leg 325 of stacked and suitably fastened electrical steel laminations. The winding leg 325 mounts the windings P and S1 at its left end, one on top of the other and hence closely coupled; the windings S1. and Sx at the right end, also one on top of the other and hence closely coupled; and the winding Se in the center, loosely coupled with the other windings. There are magnetic shunts 314 and 327 between the center winding Sc and the ends of the winding leg formed of the winding leg extensions 324 and gaps 326, and the inward extensions 315 and gaps 316. The ends of the winding leg are intended to be engaged in suitably shaped recesses in the shell bridges at 328 and 329, although air gaps may be provided at one end or the other if conditions require the same. The winding S1 is mounted on the central leg 338 of the choke 322. The choke is formed of E laminations 359 and I laminations 340 suitably stacked and fastened, and there is the usual gap 341 between the center leg 338 and the I stack.

Referring now to Fig. 8, note that the windings P, S1, S1, S0, and Sx are all connected end to end similarly to the windings of the apparatus 10. As in the case of the apparatus 10, the primary P and the first secondary winding S1 are connected to be voltage additive, and the secondary So which is somewhat the equivalent of the second secondary S2 of apparatus 10, is in voltage opposition to the voltage of S1. The winding So may be considered a leading secondary winding and is separated from the windings S1 and P by the narrow shunt 327. The winding 51: it will be noted, is in voltage opposition to the winding Sc and it may be considered the bucking leading secondary winding. Its function is similar to the function of the winding 63 of U. S. Patent No. 2,509,188 issued May 23, 1950, to me. It will be noted that this winding 51: is closely coupled with the winding S1.. This last winding may be termed the lagging secondary winding, since it serves to provide the inductive component of current during operation to assist in developing good power factor for the device.

The winding 8:; produces fiux which is in phase with the flux of the lagging secondary S1. thereby increasing its reactance during operation. This decreases its current. Balance between the lamps is achieved during operation as explained in said last mentioned patent. In addition, certain advantages with respect to copper savings are achieved. The principal function of winding Sx is an improvement of wave shape of the current of the apparatus by prevention of saturation in the corein the vicinity of the winding So. I. i

The device 300 is constructed quite similar to the previously described apparatus; The primary winding P has leads 331 and 332 connected respectively to the line terminals 333 and 334. The winding S1 and leads 335 and 336, the first of which is connected to lead 332 at juncture 337 and the second of which is connected to the choke winding S1. The opposite terminal of the winding S1 is connected to So by lead 342. Lead 350 extends between windings Sc and Sx. One lamp L1 is connected across windings P, and S1 and S1 by leads 344 and 345 which join leads 331 and 342 respectively at junctures 346 and 347. The second lamp L2 is connected across the windings S1-S1', Sc, and Sx by the leads 343 and 348 which connect respectively with the free terminal of the winding Sx and the lead 332 at juncture 349. The winding 51. is connected in auto-transformer relationship with the primary P by lead 351 connected to lead 332 at juncture 349, and in series with lamp L3. Lead 352 connects lamp L3 with the winding Sr. while the lead 353 connects lamp L3 with lead 331.

As in the case of previously described apparatus, the apparatus 300 is a seriatim starting, series operating device, but consists basically of two parallel circuits, one drawing a leading current, and the other drawing a lagging current. The lagging circuit includes the lamp L3, while the leading circuit includes the other two lamps. Thus, when the primary P is energized, the lamp L1 will ignite. It will be subjected to the voltage of the primary P and the secondary S1. Simultaneously the lamp L3 will ignite in parallel operation. Thereafter, the lamp L2 will be subjected to the combined voltages of S1 S1, Sc, and Sx. The voltages of S1 and So will be considerably greater than the voltages of S1 and 51: which has very few turns, and hence the lamp L2 will ignite. Thereafter, current will flow principally in a series circuit through Sc and Sx, P and the lamps L1 and L2. The high inductance of the branch including S1 opposes flow of current therethrough.

In Fig. 9 I have illustrated an apparatus 400 which is similar to the apparatus 300 in many respects. The equivalent elements are designated by the reference characters used previously except that they are prefixed by the numeral 4. The principal difference between apparatus 300 and apparatus 400 is the same as the difference 'between apparatus 10 and apparatus of Fig. 5. In apparatus 400, the lamp L1 is no longer connected across windings 51-81 and P, but is only across the auxiliary starting windings S1S1. Likewise the lamp L2 is now connected across all of the windings in the leading current branch. The lagging current branch, including lead 451, Sn, lead 452, L3 and, lead 453 is identical to that of Fig. 8. Thus, the primary P is energized from line 433 and 434 through leads 431 and 432. The number of turns of winding S1 is sufficient in and of itself to ignite lamp L1 through leads 444, 445, condenser C, juncture 447, choke winding S1, and lead 4'36. Primary P connects with secondary S1throu-gh lead 435 connected to juncture 437 on lead 432, The circuit for igniting lamp L2 includes all windings with their voltages added in series. The circuit may be traced from opposite terminals of lamp L2, starting with lead 448, juncture 446, P, lead 432, juncture 437, lead 435, S1. lead 436, S1, lead 42, So, lead 450, Sir and lead 443. The theory of operation and the advantages achieved have been explained hereinabove.

In Figs. 7, 8, and 9 referred to above, certain features of the apparatus there described are also described and claimed in my co-pend-ing application Serial No. 160,366, filed May 5, 1950, having the same title as the instant application. To the extent that the subject matter hereof is common therewith, this application comprises a continua-tiou-in-pa-rt thereof.

In Figs. 10, 11, 12, and 13 I have illustrated apparatus which is designated 500, '600, 700, and 800, the principal differences there-between being'in the arrangement of thewindin-gs. Eachembodies'my invention as applied to a ingle "lamp ballast, and hence the elements are all designated by the same --re'terence characters used Ehereto'fore, except for the additional prefixes 6, 7, and "8 respectively.

' "To the extent that the apparatus of *Figs. 10 to 13 inclusive have subject matter in common with my copending application Serial No. 168,219, filed June 15, 1959, this application is a continuation-in-part thereof.

Basically, the apparatus of Figs. 10 -to;l-3 inclusive difier from the apparatuses of the last-mentioned "coipending application in that instead of the winding S1 being loosely coupled With-the primary, in this application the winding is closely coupled with the primary 1 and a high inductive reactance choke winding S1 'is provided in series with the winding S1 to form together therewith what I have-termed the auxiliary starting winding. In this manner I am able-to achieve the advantages enumerated above, together with all of the additional advantages inherent in the apparatus shown, described and claimed in said .co-pending application Serial No. 168,219.

=Since the operation of the apparatuses of these four figures is explained in some detail in the said co-pending application, and as well hereinabove in connection with variations of the invention, no detailed explanation will be given. Short descriptions will however point out the ditferen-ceslbetween the respective apparatuses.

The apparatus 500 is an auto-transformer arrangement. Actually it is identical to apparatus 10 except that lamp 5L1 has been removed. When P is energized, current flows due to the voltage induced in S1. When current flows, a voltage developed in'S1'. combines "with voltage induced .in S2 to ignite the lamp L2. Since Si is ahigh inductance winding, the circuit for flow of most current during operation :is lead 532, juncture '549, lead 548, lamp L2, lead 543, winding S2, lead 542, juncture 547, condenser C, lead 544, juncture 546, and lead 531. The leads "531 and 532 connect the primary winding P with the line terminals 533 and '534.

The apparatus600 is another auto-transformerarrangement which is substantially identical to the apparatus 100 except for the absence of the lamp L1. When P is ener- "gized, flow :of current caused by the winding S1 will :develop -a:voltage in S1", which, when added'to the voltages -.of P and S2 will ignite lamp L2. The current path during operation is substantially a series-path by-passing the auxiliary starting Winding S r- S1" through the condenser branch comprising juncture 647, lead 644, confdenserC, juncture 646, and 'lead632.

The apparatus 700 is substantially identical to apparatus '500 except that another'choke Winding CH has 'fbeen inserted between lamp L2 and winding '82. It connects with S2 by lead 750, and with L2 by lead 743. This choke may be a ltype operating below saturation for improvement of the Wave shape of the apparatus, and the physical construction of the transformer may include an end window separated from the remainder of'the transformer by a magnetic short circuit, as shown .and described in my co-pending application Serial No. 182,212, filed'August '30, 1950. 'If'desired the choke .CHcanbze a physically separate element .as is the choke 22.

The apparatus 800 is identical to the apparatus .500 except that the left hand terminal of the lamp Lzjsxconnected .to the left .hand side of the :primarywindiqg This will ,in some measure neccssitate adjustment :of the voltage deyelopedin S2 butin all other respects the Operationis identical.

It should .be appreciated, without the necessity oft-urther illustration that the apparatus illustrated need-not be connected in auto-transformer:relation,but'may be arranged so'that the primary winding ;'P idOeS snot t-ak-e part in ignitien 'ot he-lamp .Lz. JI-hisihas been illustrated in-other apparatuses herein. lt-shni1ldalsobeunderstood alhat athe transformer-chokeconstructions shown and de- .last ikIlOWl'l .zas "5briol .type :ballasts. :portion 92lisashownrin the ,center'formed of interlaced E -'s.cribedfin-rconnection with "Figs. "2 and 4 are suitabledor use with the apparatuses-"of Figs. 10 to 13"inclusive.

InFig. 14 "I have shownan apparatus-9llil which is "a further"modification'ofthe invention. In this device-the 'ingSr'. The "operating winding is formed of secondary winding S2 and choke'windingSz'.

Considering the apparatus in detail, the primary winding Pis'connectedbyleads931 and 932-to the terminals 33 and 934. The first secondary S1 has one lead 935 connected to lead 932 at juncture i937, and "its -other -1ead'-93'6 connected toone-side-of the lchokewinding si. The'winding -S1 hasits other side connected by lead'i9 42 toWinding-Sz" which-in tu-rn'is connected in series with winding '82 through lead 950. Winding 'S2 is in series with lamp L2 with -which it is connected by lead 943. 'The lamp L2 is connected by lead 948 with the =1e'ad "932 at-juncture 9 49. The lampLi is connected across the primary-P an'd'the-win'dings SiS1"-'through leads 944-and 945 to terminals 946 and 947 with the condenser 0in lead 945.

From an examination of Figs. 1 and 14, it will be obvious that the only =diiference lies in ithe addition "of the winding'Si'iinseries with 82. Likewise, the winding 82 is now'closely .coupledltoithe primary :P.

Theconstruction of :the magnetic portion 929 'of the apparatus 9.90 follows generally the construction. of balzThe transformer .laminations :or ;'E3s ;and Is, the :choke 922is shown on :the rightccarrying thewwindingSr, and the 923-is shown :Qnjtheileft:carryinggthe winding S2. .Each of the :chokes :isformed of ';E and I .laminations designated .924and 5925 with :a gap 926gforrned between the'central leg 927 of each and theiLlaminationQZS. It is .also:possible to .elimin-ate the :Ils 0f the end chokes and butt the 'wEs to thecentral portion using each end of the central transformer as a common leg respectively with each choke. This is shown in Fig. 15.

A .consideration of the divers embodiments of the invention shown .and described hereinabove together with ,a reexamination of their explanations will bring out certain important-facts. \Infevery examplethere .are the following structural features common to all forms of the invention: there are at least "two magnetic circuits; there is .at least a primary winding, anxauxiliarystarting winding, .anda .second secondary winding; the auxiliary starting windingis acompound Winding comprising two physically separate "windings connected "in series :and each .mountedfin cooperative association with a differentwore .of :thc vzsaid magnetic :circuits; *of the windings. comprising the compound auxiliary starting winding, one is acfirst secondingwindingclosely coupled with the primary and connected in :onenragnetic circuit, and the other is high inductive reactance winding associated with .-the second magnetic circuit; the second secondary winding is ahig'h .Tle'akagereactance winding associated with the first rnagnet'ic circuit vand arranged in voltage bucking relationship to thefirst secondary winding; there are means for starting a flow of current through said high inductive 'reactance winding when the primary winding is 'energizetlffrom a suitable -A. C. line; said last 411E71- tioned means is connected across .the windings cfthc device excluding the .lsecondsecondary winding and inc'luding atjle'ast the auxiliary starting'winding, and may comprise a gaseous :discharge device, .er a condenser, or :i

I gaseous dischargedischargeand condenser in series; there is a voltage relationship between the second secondary and the auxiliary starting winding such that when current flows in the high inductive reactance winding portion, a voltage will be developed therein additive in nature to the open circuit voltage of the second secondary; there is a gaseous discharge device connected across the windings of the apparatus including at least the second secondary and the auxiliary starting winding; after flow of current in the high inductive reactance winding, the voltage across the gaseous discharge device will be suflicient to ignite same.

The above enumerated features are capable of being used with many changes in the device. For example, there may be additional windings; there may be additional gaseous discharge devices; there may be additional magnetic circuits; there may be connections resulting in autotransformation and straight transformation; and there may be circuits connected with the basic circuit for igniting and/or operating gaseous discharge devices in other manners. None of these variations will in any way affect the operation of that portion of the apparatus which comprises the invention.

Basically reiterated the magnetically coupled winding portion of the compound auxiliary starting winding acts to cause current to flow in the loop including the choke winding; this is done either with or without the ignition of a first gaseous discharge device; thereafter the voltage across the second secondary winding is increased due to voltage developed in the choke winding and the resultant potential is sufficient to ignite the second gaseous discharge device. When current is flowing through the apparatus, the greater portion thereof by-passes the auxiliary starting winding.

It is again mentioned that the invention is to be limited in scope only by the broad statements of structure as set forth in the appended claims irrespective of the theory of operation ascribed to the apparatus.

What is claimed and desired to be secured by Letters Patent of the United States is:

1. Apparatus of the character described and including a plurality of gaseous discharge devices, a low voltage source of alternating current, means for igniting and thereafter operating said gaseous discharge devices from said source which comprise, a transformer core and a choke core forming two separate magnetic circuits one in each respective core, a primary winding mounted on the'transformer core, a composite starting winding having two parts, one part comprising a first secondary winding mounted on the transformer core in close coupled voltage-inducting relationship with the primary winding and the second part comprising a highly inductive winding mounted on the choke core in non-inductive relation to the primary winding and connected in series with said first secondary winding, a second secondary winding mounted on the transformer core and in loosely coupled voltage-inducing relationship with the primary winding to have high leakage reactance during operation of the apparatus, al of the windings being connected end to end in the order hereinabove named, a condenser, the primary winding being connected across the source, one of said gaseous discharge devices being connected in a loop across windings of said apparatus including said condenser in series and at least the starting winding but excluding the second secondary winding, and a second gaseous discharge device being connected in a second loop across windings of said apparatus including at least said starting winding and saidsecond secondary winding, the open circuitvoltage relationship between the secondary windings in the second loop being bucking, the turn relationship between the primary winding and the windings of the first loop being such as to provide sufiicient induced voltage therein to first ignite the first gaseous discharge device when the primary winding is energized from'the source, the second part of the composite starting winding having no contributing voltage to aid in the starting of the first gaseous discharge device, and there being a voltage produced in the said second part of the composite starting winding after the ignition of the first device which causes flow of current through the said first loop, the relationship between said last mentioned voltage and the open circuit voltage of the second secondary winding being additive whereby after ignition of the first device the resultant voltage of the windings of the second loop will be sutficient to ignite the second gaseous discharge device.

2. Apparatus as described in claim 1 in which the first loop includes the primary winding, and the voltage relationship between the primary winding and the first secondary winding is additive so that upon said energization of the primary, the combined voltage of the primary and first secondary will be sufiicient to ignite said first gaseous discharge service.

3. Apparatus of the character described and including a plurality of gaseous discharge devices, means for igniting and thereafter operating said gaseous discharge devices from a low voltage source of alternating current which comprises a transformer core and a choke core, a primary winding mounted on the transformer core, a starting winding having two parts, one part comprising a first secondary winding mounted on the transformer core in close coupled relationship with the primary winding and the second part comprising a highly inductive winding mounted on the choke core and connected in series with the first secondary winding, a second secondary winding mounted on the transformer core and loosely coupled with the primary winding to have high leakage reactance during operation, all of the windings being connected end to end, leads connecting the primary winding across said source, a condenser, means including electrical conductors connecting one of said gaseous discharge devices in a loop in series with said condenser and said starting winding, means including electrical conductors connecting a second gaseous discharge device in a second loop including at least the starting winding and the second secondary winding, the voltage relationship between both secondary windings being in opposition, and between the highly inductive winding and the said second secondary winding being additive, but only after current flows in said highly inductive winding, whereby when the primary is energized the open circuit voltage across the first gaseous discharge device will be sufiicient to ignite the same, but the voltage across the second device will not be suflicient to ignite the same, but thereafter, the flow of current through the said highly inductive winding will give rise to a voltage which will aid in igniting the second discharge device.

4. Apparatus as described in claim 1 in which the second loop includes only the second secondary winding and the starting winding.

5. Apparatus as described in claim 1 in which the second loop includes the primary, second secondary, and starting windings.

6. Apparatus of the character described including a plurality of gaseous discharge devices, including means for igniting and operating at least a pair of said gaseous discharge devices from a low voltage A. C. source, which includes an auto-transformer having a primary winding. a closely coupled first secondary winding having one side connected to one side of the primary winding and in additive voltage relationship thereto, and a second secondary winding loosely coupled relative to the other two windings, a choke having a high inductive reactance winding and being connected between the two secondaries, the secondaries being arranged in voltage bucking relationship one to the other, means including a capacitive reactor connecting one of said devices across the primary, first secondary and high inductive reactance winding, means connecting the second 'of saiddevices ac"oss the secondaries and the high inductive reactance winding, and means connecting the primary to the source.

7. In apparatus of "the character described'including at ,least a'pairioigaseous discharge devices and means for igniting and thereafter regulating "the operation of said gaseous discharge devices from a source of ,A. C. voltage "substantiallytless than the igniting voltage of the individual devices, a multiple winding transformer and a 'c'hoke'ihaving 'a'high inductive reactanjcewinding, the transformer having a primary winding and two sec- 'ondaries, and 'the choke windingbeing connected in series with the first of said secondaries, the secondaries being arranged in voltage "bucking relationship one .tothe other with "reference to a circuit "including both secondaries, lead means includingia series capacitive reactor connectingoneof said devices across apart of said transformer and said choke winding and including at "least 'the first secondary and excluding'the second secondary, lead means connecting a second or said tdevicesacross windings of =the transformer and the choke winding including at least both of said secondaries, said windings and primary having a turn relationship to produce upon energization of the primary-a voltage across the first device 'sufiicient to ignite the same, but across the second device insu'ificient to'ignite the-same, said choke winding having a sufliciently high inductive =reactance that when current flows therethrougha voltage 'will be de- 'veloped therein of magnitude and phase which when combined with the voltages of said first-mentioned part 0f the transformer and the'capacitive reactor willresult in a voltage additive to that. of the said second secondary sulficient to cause the ignition thereof.

8. The combination with a pair of gaseous discharge devices of a ballast of the character described for ig- -niting and thereafter operating said pair of gaseous discharge devices from a source of-Aq'C. voltage substantially less than the ignition voltage :of either device which comprises a :pair of electromagnetic structures, one structure having a primary wind-ing and leads for connecting same to the said source and -a secondary winding on the :firststructure in transformer relationship to the primary and loosely coupled therewith, there being a starting winding having two parts the firstpart mounted on the first structure in close-coupled transformer relation relative to the 'primary,"and reverse voltage relation to the secondary and the second part mounted on the secondstructure, lead'means forming t-wo separate loops with the respective discharge devices, the starting winding being common :to each loop, the respective parts of the starting windings providing voltages to ignite the respective devices in the :said loops seriatim, and after ignition acquiring .irnpedanceto flow of current to cause the principal fiow.'to .occurin-series with the said devices.

9. The combination with apairof gaseous discharge devices of a ballast of the character describedzfor .ig- .niting and thereafter operating said ,pair zof :gaseous discharge devices from a source :of A. C. voltage substantially less than the ignition voltage of either :devicei'which comprises a pair of corestructures, a primary winding, .a starting winding, and a secondary winding, the primary winding-and secondary windingbeing mounted on the first core structure in loosely coupled relation one to the other, the starting winding having two parts, one being mounted on said first core structure closely coupled with the primary and the second part being mounted on the second core structure, beans including leads connecting'the gaseous discharge devices to the windings, the respective parts of the starting winding serving to ignite the respective devices, the devices "being connected in two loops, the first loop including at least the starting winding and excluding the secondary winding, and the second loop including at least the starting winding and secondary winding, the devices being adapted to'be ignited seriatim with the first part of 'thestarting windringproviding atleast a part of the *voltage :for igniting the first device (when :the vprimary; .is energized, :and the second part of the starting winding providing at least a part of the voltage for igniting the second device but only after the Jfirs't device is ignited an'd the current Iflows in said second part. 7

10. The combination with a pa'ir o'flgaseous discharge devices of a ballast of the character described .ffQr igniting and thereafter operating said pair of gaseous charge devices from a source of AQ C. voltage substantially less than the ignition voltage ;of either device which comprises *a pair of core structures atpfimary winding, a starting winding, and a secondary winding, f the primary Winding and secondary winding being mounted on the first core structure in loosely coupled relation one to the other, the starting winding having two parts, one being mounted on said first core structure closely coupled with the primary and the second partrbeing mounted on the second core structure, means including [leads connecting thegaseous discharge devices to the windings, the respective parts of the starting winding serving to ignite the respective devices, the deviices being connected in two loops, the first loop including at least the starting after the first device .is ignited and the current flows jin said second part, the second'part of the starting *winding having high inductive reactance whereby after 'both devices are ignited flow of current through said starting winding will be resisted forcing the greater part off said current to -flow substantially in series through the devices and the secondary.

11. Apparatus of 'the character described igniting said gaseous discharge devices and operating the same with. desiredregula'tion from an A. C. source of voltage insufficient to ignitete'ither device comprising an auto-transformer, having a primary conjnccte d across the source forestablishing a voltage egual to the source therein, a first inductively reactive; portion o'f saidjtransformer closely coupled to the primary and of relationship relative to the primary for having aivoltageinduced therein substantially greater than the source voltage whereby the combined'volta'ges Will suificeito ignite one of said devices,means impressing the:combine d voltages of the primary 'and the .saidfiist reactive "portion across said device ;for igniting the .same including a high inductive reactance choke magnetically separatef'from said auto-transformer and in series 'with ,s aidf'first inductively reactive 'portion'and leads connecting -said one of said devices across the combined primary, reactive portion and choke, a second inductively reactive portion of said transformer of high leakage and of relationship 'relative to the primary "for having a voltage inducedtherein greater than the source voltage but bucking the "same, said first portion and choke producingafter-ignition of the first device a voltage having 'a component additive relative to the said buc'lingvoltage-whereby-thesum of said after ignition voltage and bucking voltage w'i'llbe sufiicient to ignite said second device, and =meansj-for impressing the said sum upon the second or said devices auto-transformer, having a primary connected across the source "for establishing :a svolta'ge equal to the isource .therein,:a first inductively reactivezportion of :saidftransformer closely coupled to the primary and of relation including a pair of gaseous dischargedevices, comprising means for.

ship relative to the primary for having a voltage induced therein substantially greater than the source voltage whereby the combined voltages will sufiice to ignite one of said devices, means impressing the combined voltages of the primary and the said first reactive portion across said device for igniting the same including a high inductive reactance choke magnetically separate from said auto-transformer and in series with said first inductively reactive portion and leads connecting said one of said devices across the combined primary, re active portion and choke, a second inductively reactive portion of said transformer of high leakage and of relationship relative to the primary for having a voltage induced therein greater than the source voltage but bucking the same, said first portion and choke producing after ignition of the first device a voltage having a component additive relative 'to the said bucking voltage Whereby the sum of said after ignition voltage and bucking voltage will be suflicient to ignite said second device, and means for impressing the said sum upon the second of said devices to ignite the same including leads connecting the second device across the combined first reactive portion, choke and second reactive portion, said first mentioned means also including a series connected capacitive reactor.

13. In apparatus of the character described including a pair of gaseou discharge devices, means for igniting said discharge devices and operating same from a low voltage source of alternating current, which comprises a transformer having a primary, a first secondary, and a second secondary, a high inductive winding in series with the said first secondary and magnetically separated from the transformer, leads connecting the apparatus to a discharge device, said leads being in a series circuit including the primary, first secondary and high inductive winding, leads connecting another discharge device in a loop which includes both secondaries and the high inductive winding with the open circuit voltages of the secondaries in opposition in said loop and which excludes the primary, the first secondary being closely coupled to the primary and the second secondary being loosely coupled to the primary, and the reactance of the said high inductive winding serving to impede flow of current through the said first secondary and the high inductive winding and thereby forcing the most of the current to flow through the said devices in series with the said second secondary after ignition of the devices.

14. Apparatus including a plurality of gaseous discharge devices and having means for igniting and thereafter providing the operating voltages for said gaseous discharge devices from a source of A. C. voltage of a value less than the igniting voltage of any of said devices which comprises a transformer core and a choke core, a primary winding having means connecting the same to the said source, a starting winding comprising two parts, the first part being a first secondary winding and the second part being a highly inductive choke winding, a second secondary winding adapted to carry a leading current, a third secondary adapted to carry a lagging current, and a fourth secondary adapted to function as a bucking leading secondary, all of the windings being mounted on the transformer core except for the choke winding which is mounted on the choke core, the secondaries being arranged in transformer relationship relative to the primary with the first secondary and bucking secondary in voltage reenforcing relationship, and together in voltage opposition relative to the leading secondary, the lagging secondary being in auto-transformer relationship with the primary, loosely coupled to the primary, and closely coupled with the bucking secondary, the starting winding and leading secondaries being connected end to end with the first secondary closely coupled with the primary and the leading secondary loosely coupled relative to the primary, and the leading secondaries being connected in series, a condenser means including leads connecting one gaseousdischarge device in a loop in series with said condenser and including at least the starting Winding and excluding the lagging and leading secondary windings, means including leads connecting a second gaseous discharge device in a loop including at least the starting winding and leading secondary windings and excluding the lagging secondary Winding, and means including leads connecting at least one additional gaseous discharge device in a loop including the lagging secondary winding and the primary, the first and second of said loops serving as a seriatim starting series operating leading circuit, and the third loop serving as a lagging circuit, the said bucking winding serving as a wave shape correcting device.

15. Apparatus as described in claim 14 in which the first loop includes the primary winding, the primary winding being connected in voltage additive relationship to the said first secondary winding, and in which the second loop excludes the primary winding.

16. Apparatus as described in claim 14 in which the first loop excludes the primary winding, the primary winding being connected in voltage opposition relationship to the first secondary but in voltage additive relationship to the leading secondary winding, and in which the second loop includes said primary winding.

17. Apparatus as described in claim 14 in which neither of the first two loops includes the primary winding.

18. The combination with at least three gaseous di charge devices of a ballast for igniting and subsequently regulating the operation of said gaseous discharge devices from a source of A. C. power having a voltage substantially less than the ignition voltage of any of said devices, which comprises a pair of cores, one being a unitary elongate core having mounted thereon a primary winding, a secondary winding connected in auto transformer relationship to the primary and adapted to have leading current flow therethrough during operation, another secondary winding also connected in autotransforrner relat-ionship to the primary winding and adapted to have lagging current flowing therethrough during operation, means including electrical leads and a condenser, said condenser being connected in series with the leading secondary winding and the leads connecting a pair of gaseous discharge devices to be series fed by said primary and leading secondary winding whereby during operation said devices will draw leading current by virtue of said condenser, means including electrical leads connecting at least another gaseous discharge device to be series fed by said primary and lagging secondary windings whereby during operation said last mentioned device will draw lagging current by virtue of the inductance of said lagging secondary winding, said lagging secondary winding being loosely coupled relative to the primary to develop high leakage reactance therein, and means for igniting the two first-mentioned devices seriatim comprising a starting winding having two parts, the first part being a secondary winding closely coupled with the primary and the second part being a 'high inductive reactance choke winding mounted on the second core, the first part serving to ignite the first device when the primary is energized, and then after current is flowing in the second part the said second part developing a voltage additive to the voltage of the leading secondary winding to ignite the second device.

19. A gaseous discharge device igniting and operating system adapted to be energized from a low voltage A. C. source which comprises a pair of magnetic cores, a primary winding, a starting winding formed of two series connected parts one being a first secondary and the other being a highly inductive choke winding, a second secondary Winding, and a third secondary winding, the starting winding and second secondary being connected end to end with the first and second secondaries in transformer relation to the primary with the first secondary closely coupled thereto and the second secondary loosely ance of the said third secondary winding, a second gaseous discharge device connected in. a loop including of the windings, at least the starting-winding, but excluding the second and third secondary windings, there being a series condenser in the loop and the device adapted to be ignited when the primary is energized, and a third gaseous discharge device connected in a loop which includes of the windings at leastthe'starting andtsecond secondary Windings but which excludes; the. third secondary winding, said third discharge device adapted. to be ignited only after the ignition of thesecond discharge device causes current to flow in the choke Winding,

20. A system as described in claim 19 in which there is a fourth secondary winding inseries. with the second secondary winding, mounted .on thesaid first core closely coupled With the third secondary winding and in reverse voltage relationship relative to the second secondary winding whereby to prevent saturation in the vicinity of'the second secondary winding by decreasing the flux density thereat.

21. A gaseous discharge device igniting an operating system adapted to be energized from. a low voltage A. C. source which comprises a pair of magnetic cores, one mounting a transformer and the other mounting a choke, a primary winding mounted on the transformer core and having a starting winding connected: to one side thereof,

and a loosely coupled secondary winding connected to secondary winding tightly coupled with the primary winding, and, together with the loosely coupled secondary, mounted onthe transformer core, and the second winding of the starting winding being a highly inductive choke Winding mounted on the choke core, the primary winding being connected to the source, a gaseous discharge device connected across the starting and primary windings to provide a loop, a series condenser connected in the said loop, and a second gaseous-discharge device connected across the starting and secondary windings, the secondaries being arranged in voltage opposition on open circuit in a loop containing both, the turn ratios being such that when the primary is energized the voltages of the primary and first secondary combined will sufiice to ignite thefirst device, and after ignition, the voltages in the loop and including 'that'of' the choke winding will'combine to givea voltage additivet'o that of the second secondary and suf'nci'ent to ignite the second device, the inductivereact-ance of the choke winding being instrumental inforcing substantially allof'the operating current to flow in series through thedevicesand the second secondary and by-passing the starting winding.

' References Cited'in the file of thispatent UNITED STATES PATENTS 1,930,123 Ewest- Oct. 10, 1933 2,269,978 Kronmill'er Jan, 13, 1942 2,439,976 Keiseri Apr. .20, 1948 2,504,549 Lcmmers Apr. 18, 1950 2,518,767 Freeman Aug. 15, 1950 2,558,293 Feinberg. June 26, 1951 

